Storage battery, separator therefor
AssigneeYuasa Battery Co., Ltd.
InventorsKazuo Murata, Shiro Tanso, Junzo Yamao
Life of this patent
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Abstract
The present invention relates to a high performance lead-acid storage battery having a special microporous separator between a positive and a negative plate in a cell of the battery. The separator is comprised of a microporous embossed thin sheet having many small projecting embossed parts which provides unique characteristics in a cell including low electric internal resistance in the cell, sufficient electrolyte between the plates in the cell and sufficient elasticity of the separator to prevent active material shedding, thereby giving a high performance at a high rate of discharge and long life.
Claims18
A lead-acid storage battery comprising a container, at least one set of battery plates, one plate of the set being a positive plate and another being a negative plate, and a separator interposed between the positive and negative plates, the microporous separator comprising a microporous sheet of heat meltable synthetic resin containing film of less than 0.5 mm in thickness and having submicron micropores, said microporous sheet having a plurality of independent limited embossed parts projecting outwardly from the separator toward the positive plate, each of said projecting embossed parts being substantially less than 1 cm.sup.2 in area and the height of the embossed parts being less than 1.5 mm, the number of embossed parts on the sheet being more than 50 per square 100 cm.sup.2 of sheet, the projecting embossed parts being connected substantially with projecting embossed channels which help gas formed in the cell escape upward out of the cell, the height of the projecting embossed channels being lower than the height of said projecting embossed parts, and the pores of said embossed parts being at least partially closed.
A separator adapted to be interposed between a positive and negative plate in a lead-acid storage battery comprising a microporous sheet of heat meltable synthetic resin containing film of less than 0.5 mm in thickness and having submicron micropores, said microporous sheet having a plurality of independent limited embossed parts projecting outwardly from the separator, each of said projecting embossed parts being substantially less than 1 cm.sup.2 in area and the height of the embossed parts being less than 1.5 mm, the number of embossed parts on the sheet being more than 50 per square 100 cm.sup.2 of sheet, the projecting embossed parts being connected substantially with projecting embossed channels, the height of the projecting embossed channels being lower than the height of said projecting embossed parts, and the pores of said embossed parts being at least partially closed.
Dependencies are inferred from the claim text.